Idle Air Control Valve

[SiK FoX]

How do i know if my IAC is bad? Ive done the idle reset but my fox is still having small issues. When i come to a stop the idle stays at just over 1000 for about 10 seconds, but eventually falls to 800 and stays there. During my idle reset, i didnt notice a change in my idle when the IAC is either plugged in or unplugged. Ive cleaned it out with carb cleaner and the rod on the inside moves freely but idk. Any ideas?

 

[Mustangcwo]

Typically, when the RPM hangs for some time and then drops to normal there is something in the tune. Is this a new problem? If you believe the IAC is your problem, it's easy to take off, tear down and clean.

 

['03snkbt]

toss up between IAC and TPS? would recommend pulling intake and cleaning MAF, IAC, TPS and TB. then try to re-diagnose.

 

[wickedstangs]

How do i know if my IAC is bad? Ive done the idle reset but my fox is still having small issues. When i come to a stop the idle stays at just over 1000 for about 10 seconds, but eventually falls to 800 and stays there. During my idle reset, i didnt notice a change in my idle when the IAC is either plugged in or unplugged. Ive cleaned it out with carb cleaner and the rod on the inside moves freely but idk. Any ideas?

This is really easy to test. First as with all problems you should gather the trouble-codes from the computer. Follow the codes for testing and repair. If you get a code that points to a problem with the IAC start the vehicle and bring the engine up to operating temperature. Allow the engine to idle without any driver input to the throttle or pedal. Go under the hood, and disconnect the electrical connector to the IAC. If the engine begins to stubble or stalls the IAC is functional and does not need to be repaired. If the engine idle does not change you should remove the IAC for inspection.

The IAC can pass and still need repair, or it can fail and not need replacing. The plunger and internal spring can get clogged with dirt and oil. This will slow down the air flow and not allow the IAC to function properly. Remove the IAC and clean it. There are 2 halves to the IAC, and you can not buy just one half, but you can take it apart to clean it. But if the internal solenoid is faulty the IAC needs to be replaced.

 

[SiK FoX]

yeah its the IAC. whens its unplugged nothing changes...looks like im gonna go get a new one this weekend

thanks guys